Return of the Sea Otter

by Todd McLeish

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  REGARDLESS OF WHAT caused the sea otter population in the Aleutians to crash—and who agrees or disagrees with that explanation—I wanted to see for myself what sea otters there were facing. I tried for two years to get on a research ship conducting periodic surveys of sea otters in portions of the island chain, but by the time each ship departed there were always too many scientists and not enough berths available to squeeze me in. So Renay and I trekked there on our own.

  We flew into Unalaska Island, in the eastern third of the Aleutians, the most populous island in the chain and the one best known—at least recently—as the home base of the fishing vessels shown on the reality-television program Deadliest Catch. At first glance, Unalaska was nothing like I expected. I knew of its volcanic origins, but its steep, rocky slopes jutting up more than two thousand feet from the water’s edge certainly made an unexpected impression as we arrived. Unlike Southeast Alaska and almost everywhere else I had visited in Alaska south of the Arctic Circle, the island was entirely treeless, save for a few spruces planted by soldiers during World War II. Instead, it was covered in lush grasses and wildflowers with scattered blueberry and salmonberry bushes. And though the island is the southernmost point in Alaska, closer in latitude to balmy Vancouver, British Columbia, than to the state’s capital, many of the hillsides were still covered in snow on the first of July.

  To cap it off, the island appeared to be relatively unaffected by the massive drop in sea otter numbers that the rest of the Aleutians have experienced. We noticed a few animals almost everywhere we turned. At least at first. A lone sea otter was in view from the airport terminal when we arrived from Anchorage, and as we ate our breakfast the next morning, we watched a grizzled male hard at work cracking open clams in a small inlet behind the island’s only hotel. We saw a few other scattered individuals as well, but after a day of wandering around, our total was only six. Yet just a tiny corner of the 1,051-square-mile island is accessible to humans—the rest is roadless and uninhabited except by ptarmigans, lemmings, a few songbirds, and introduced Arctic ground squirrels and red foxes—so we figured there were plenty of other places the otters may reside.

  About 4,300 people live on Unalaska and over a bridge to the tiny adjacent Amaknak Island, the largest human population anywhere in the Aleutians. Most work in or cater to the fishing, fish-processing, and marine-construction industries. Dutch Harbor, on Amaknak, is the nation’s most productive fishing port, with 762 million pounds of pollock, salmon, king crab, and other species harvested in 2015 from the Bering Sea to the north and the Pacific Ocean to the south. Overlooking the harbor and scattered throughout the hillsides are moss-covered remnants of World War II fortifications and gun emplacements, evidence of the island’s little-known military history as the only US site besides Pearl Harbor to be bombed by the Japanese.

  After getting the lay of the land and taking a day to get used to the unusual daylight hours—sunrise at six thirty and sunset at midnight—Renay and I drove the length of every coastal road in the region to get a better sense of how the sea otter population was faring in the island’s waters. We started at Unalaska Bay, across from our hotel, which was flat calm at dawn and absent of almost any wildlife save a small flock of harlequin ducks, several distant Dall’s porpoises, and the ubiquitous pigeon guillemots, a mostly black seabird that was often the only bird species visible on the water. So we continued south along Captains Bay, where the noise from commercial fishing boats and seafood transport vessels was drowned out by the hum of fish processing plants; an absence of kelp in the bay suggested that otters weren’t likely to be found in any numbers. We counted zero.

  After a detour over and around Mount Newhall, we returned to the coast east of town at Summer Bay and Morris Cove, both absent of sea otters and almost any other wildlife. But as we rounded the corner toward Iliuliuk Bay, a fifty-foot-tall rocky spire called Little Priest Rock guarded a four-mile stretch of coastline where abundant kelp extended about one hundred yards offshore. Just beyond the spire we saw our first otter of the day, resting nearly motionless in the blustery cold. It made us feel optimistic about the upcoming shoreline, but that optimism didn’t last long. Although we slowly scanned every piece of kelp and every bit of open water, we found no more otters. We were rewarded instead by several small groups of horned puffins, a couple Steller sea lions, more pigeon guillemots, and dozens of bald eagles. No otters were present in the tiny coves in town, either, even in the places we had seen individual animals the day before.

  Our last chance was at the spit, a mile-long natural barrier that protects Dutch Harbor and the numerous ferries, Coast Guard vessels, research ships, and fishing boats docked there. It was a noisy place, as construction vehicles raced around twenty-five-foot-high stacks of crab pots covering every available spot of land. But on the outside edge of the spit, across Iliuliuk Bay from the stretch of kelp we had just driven by, another patch of kelp finally revealed what we had come nearly five thousand miles to see. A raft of about twenty sea otters groomed and rested just beyond the line of kelp, oblivious to our stares and even more oblivious to the abundant bald eagles—about eight hundred living in town at last count—that glared from every available perch.

  A solitary male otter materialized not far from where we watched, uniform in color and with a healthy appearance suggesting he was approaching adulthood and happily in the prime of his life. He repeatedly dived on long foraging bouts, seldom resting between each dive, and never pausing to groom during the twenty minutes we observed him. When we first saw him surface, he carried a large cream-colored clam in both paws, then rolled on his back and began to noisily crack it open. We couldn’t be sure what kind of tool he was using to crush the hard shell—it appeared to be a flat stone—but his effort resulted in a great deal of splashing, as if it were a child’s pool party. With his face turned to the side to avoid the splashing, he quickly struck the clam on the stone four or five times, paused momentarily, then repeated the process until the shell was broken enough that he could remove the flesh with his teeth. He dropped the empty shell into the water and hurriedly followed it down in search of his next course. When he reappeared, he brought up an unidentifiable white fleshy mass—perhaps a squid or sea squirt—that the otter repeatedly tugged at with both paws in an unsuccessful attempt to tear it apart. His flat rock was of no use this time. He bit it a few times, but soon appeared to decide it wasn’t worth the effort, so he dropped it and dived for something else.

  As eight other solo otters foraged in peace amid the thick kelp and a harbor seal looked on from a distance, the animal continued his foraging dives, always surfacing with something edible that required additional effort before he could swallow it. Foraging for food was hard work requiring his full attention, and never once was he distracted from his effort by the commotion of other otters or by the rumble of fishing boats docked just one hundred yards away in the harbor. The few times he glanced up occurred as he was chewing his food prior to diving again. He looked to be saying to himself that there was no time to waste, and given how much food each otter requires every day, he was probably right.

  I closed my eyes for a moment to concentrate on the sound of the sea otters smashing open their mollusks, though it was sometimes difficult to pinpoint the direction from which the rhythmic rat-a-tat-tats came. While I focused my ears on the sea otter drumbeat, one otter provided a new musical voice by sneezing in the distance. And as I opened my eyes and scanned the deeper water, I kept finding more and more otters, many of which were also foraging and loudly cracking mollusks. One brought up a large crab and silently broke its legs off before digging into the crab’s innards.

  My tally neared forty when the original raft of sea otters appeared to wake up at once and roll around momentarily before returning to rest. They drifted farther from shore, farther from the kelp, then seemed to split into smaller groups before recombining again. A smaller raft I hadn’t seen before paddled to join the party,
and a few brief spats erupted before everyone settled once more. And still the staccato tapping continued, like the sound of woodpeckers drilling into a dead tree.

  The seemingly healthy number of sea otters at the Dutch Harbor spit belied the true nature of the complicated Aleutian otter story, as we learned the next day. Our visit to Unalaska coincided with the conclusion of a research expedition throughout the eastern Aleutians by scientists studying kelp, urchins, and the changing ecosystem brought about by the drastic reduction in sea otter numbers. Based aboard the RV Oceanus, a 177-foot oceanographic research vessel, a team of thirteen scientists and graduate students dived to the seafloor near Atka, Adak, Tanaga, Chuginadak, Umnak, Anagula, and Unalaska Islands to assess urchin numbers, kelp health, and the diversity of other marine life in the region following the sea otter decline. While they didn’t conduct a scientific census of sea otters, they were surprised to observe an average of just one otter per island, with the exception of Unalaska.

  “They’re really scarce out there,” said Ben Weitzman, who works for Tim Tinker and is studying for his doctorate at the University of Alaska. “They don’t make themselves very conspicuous. When you observe them, it’s always very near shore, you don’t find large rafts anywhere, and they don’t hang out very far from where they can get to shore to haul out” in case a killer whale appears.

  Weitzman had participated in systematic surveys of the Aleutians the previous two years, circumnavigating each island and counting every otter found, and he said that counts were very low, especially around the western islands. Sea otter numbers hadn’t declined much from previous surveys, but because there are so few otters left, many island populations are at great risk of simply disappearing entirely.

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  WESTWARD OF THE Aleutian Islands, across the international date line to Russia’s Commander Islands and southward to the Kuril Islands, some of the same questions are being asked about the resident sea otter populations. And yet the situation there is so very different. Though separated from the Aleutians by just 207 miles, the two islands that make up the Commander Islands have a stable sea otter population numbering about seven thousand animals (though they are infrequently surveyed).

  “It basically looks exactly like the Aleutians but before the decline,” said Tinker. “You have scrawny otters that are pretty much limited by food abundance. There are killer whales there, but there’s no indication that they’re eating sea otters. The otters rest offshore in groups, oblivious to the killer whales, just like they used to do in the Aleutians.”

  The Kuril Island sea otters, however, have experienced a rapid decline in the last decade just like those in the Aleutians, although for apparently different reasons. Otter numbers in the eight-hundred-mile island chain that runs southwest from the Kamchatka Peninsula almost to Japan totaled about twenty-two thousand in the early 2000s, with more than half of that total observed around just one of the archipelago’s fifty-six islands, Shumshu Island in the north. But five years later, the population had declined by 70 percent for unknown reasons.

  According to Russian sea otter biologist Katya Ovsyanikova, who conducted an otter survey throughout the Kurils in 2012, the population decline is not likely caused by killer whales, since most of the killer whales observed in the region are residents that eat only fish, and sea otters there have not changed their behavior to avoid killer whales. She told me that pollution and human disturbance appear to be the greatest threats; while some poaching occurs, there is no market anywhere for sea otter pelts, so hunting is unlikely to be a significant concern.

  Ovsyanikova said she is particularly worried about the sea otter population at Urup Island, where she found about 850 otters during her latest survey, the second-largest population in the Kurils but less than half the number counted a decade earlier. She said the island has long been recognized for its importance to sea otters, and it was a protected nature reserve from 1958 to 2003. Despite plans to reestablish its protected status by 2018, a gold-mining operation opened there in 2013, and explosives and liquid cyanide are used to extract the gold. Ovsyanikova said the significant disturbance is placing the sea otter population at great risk, and she argues that the island should be recognized as critical habitat.

  The farther south one goes in the Kuril Islands, the fewer sea otters are found. And though northern Japan had a small historic population of otters before the fur trade, sea otters no longer inhabit the region, except for a very occasional stray animal that will wander south of the Kurils to Japan’s Hokkaido Island.

  “There’s been a couple of times that individual males have shown up there for a couple weeks, and once they had a population of two males for a month or so,” Tinker said. “But it’s at the range edge there, and what may be limiting them there, no one knows.”

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  MY VISIT TO UNALASKA ISLAND and observation of fewer than fifty sea otters clearly didn’t do much to answer the larger questions about the decline of sea otters and other marine mammals in the Aleutian Islands. But it made me ponder what may be the most pressing question for the region’s sea otters: What’s next? Has the population decline ended? What is the outlook for their recovery? And what can be done to accelerate that recovery?

  The answers to those questions are just as complicated as the explanations for the population’s decline. Most experts seem to think that it has ended, but they also see little evidence that sea otters in the Aleutians are recovering. “There are so few otters out there that it’s hard to say what the trends are,” Estes said. “I think for the last decade the population has been more or less stable at a very low density.” He noted that there are a few places where the animals have become locally extinct, like on isolated Buldir Island in the far western Aleutians, which Estes said had about one thousand sea otters at its peak but now has none. Most islands still have a few sea otters in locations where there is habitat inaccessible to killer whales, like at Clam Lagoon and around Eddy Island. In those locations, the otters are producing pups at a relatively high rate, but they’re still not growing the population.

  Why not? Estes and Tinker say it’s because killer whales still occasionally visit the islands and eat a few sea otters. “During the heyday of the decline in the early 1990s when the population really declined rapidly,” Estes said, “we saw killer whales around all the time. Every day we would see them. But now I might see a killer whale every couple of years. So I think what’s happened is that they came, they ate the otters, and they left, and now occasionally one will come back, and any otter that’s not smart enough to get out of a place that’s vulnerable will probably get eaten.”

  Doug Demaster agrees. He calls it “the predator pit,” when populations get so small that even a low level of mortality caused by predation can prevent the population from recovering. He thinks that’s what is happening with Steller sea lions in the western Aleutians and also what is happening with sea otters. “They’re going to have to survive in such low numbers that the killer whales move off or lose their cultural memory of feeding on sea otters,” he said. “My guess is that there will be local areas where the otter numbers were knocked down so far that just a few killer whales predating on them would prevent recovery. And there will be other areas where killer whales for some reason stop foraging on otters or somehow aren’t finding the otters and they’ll start recovering in those areas. So over the next twenty years, some areas will have no recovery and other areas will have reasonable recovery.”

  Sadly, there is little that can be done to help the sea otters recover more quickly. All of the animals involved—seals and sea lions, killer whales and sea otters—are protected by the Marine Mammal Protection Act. Some, like the sea otters and Steller sea lions, have dual protection under the Endangered Species Act. So it is very difficult to take steps to help one species without harming one of the others. Demaster says it may be possible to implement a program to harass the killer whales using underwater acoustics to keep th
em out of certain small areas, to allow the otters to recover. But there is no telling whether that would be successful over the long term. Federal biologists have tried such an effort only a few times, mostly to scare California sea lions away from the mouths of salmon-spawning rivers in Washington and Oregon, and it didn’t work especially well. Attempting it in a large, remote place like the Aleutian Islands would be even more challenging, not to mention extremely expensive. It would also be highly controversial—killer whales may have as many supporters among the general public as sea otters do—and likely take a long time to be approved.

  Estes has another idea. Given his belief that the otter decline was part of a cascade of effects that started with the decline of the great whales, he thinks the recovery of these whales would trigger a reverse cascade that would lead to the recovery of the Aleutian sea otters. “It’s not absolutely clear that it will run in reverse,” he said, “but I think that if someone were to ask me what’s the most likely way of fixing this problem, I’d say recover the whales.”

  If that’s really the answer, then that could be considered good news, because whale populations are recovering throughout the Pacific. Humpback whale numbers are growing, gray whales are on the increase, minke whale numbers are high, and fin and sperm whale numbers are uncertain but probably stable. But getting the next domino in the cascade to right itself may take a while, and sea otters may recover on their own in that time, regardless of what happens to the rest of the marine mammals in the region.